stuttering at low rpm's

[Bretty]

[quote author=Bretty link=topic=22602.msg260781#msg260781 date=1495059310]
Swap the spark plugs and leads from cylinder 2 and 3. Give it a good run and then repeat your spark plug check. See if the problem stays with the cylinder (carb / fuelling issue) or moves with the spark plugs/leads

After replacing the spark plugs, plug no. 2 was black after 2 km's already.
I haven't changed the leads so far...
[/quote]

(Ignore me if you already know this but...) Spark plugs 2and3 spark at the same time, but as one is on exhaust stroke and the other is on the compression stroke only one fires. So if you swap the leads over between cylinders 2and3 you can eliminate the problem being with the coil or plug cap. This is a very simple thing to do and worth eliminating before going to the trouble of removing and stripping the carbs again.

An intermittent spark could cause that spark plug to foul like that, and electrical faults can change with rev range as the mixture resistance changes. I'm not saying it IS the problem, just an easy check that is worth doing, before the ball ache that is removing and stripping the carbs again.